"Well, what I was trying to do is get this out of the way before she spends more time with her attorney," says Knadler in the recording. "Well, I gotta be able to trust you, cause I don't wanna go to jail for the rest of my life."

Knadler gave King $1,000 and promised to give him an additional $10,000 when the task was completed.

"As soon as he did that, then it all hit. I've just been paid to take part in this," said King.

That conversation in King's pickup happened about 3 p.m.

By 11 that night, Phoenix police had the recording, swooped in on Knadler's house and arrested him in the murder-for-hire conspiracy.

But while behind bars, Knadler tried to orchestrate another murder-for-hire plot, telling an undercover officer secretly taping the meeting that he wanted his wife and King both dead.

"What do you want me to do?" asks the undercover officer.

"Whack this guy," says Knadler.

King says he has lived in fear ever since making that secret recording. He is the key witness in the case against Knadler and now has brought civil cases against his former company.

He keeps his recorder in his truck as a symbol of what's happened to him over the past year and a half.

"It saved me and Libby (Knadler's wife) because one, it proved something was going to happen and it proved I wasn't lying," said King.